3 Pages in Charles Darwin's Library associated with "mental states - discontent"

The anatomy and philosophy of expression
By: Bell, Charles, Sir,
Publication info: London, John Murray, 1844
Pages: Page 140 Page 150
Mécanisme de la physionomie humaine, ou analyse électro-physiologique de l'expression des passions
By: Duchenne, G.-B. (Guillaume-Benjamin),
Publication info: Paris, Jules Renouard, 1862
Pages: Page 91